dev/codeserver/java/com/google/gwt/dev/codeserver/WebServer.java - gwt - Git at Google

 /*
  * Copyright 2011 Google Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may not
  * use this file except in compliance with the License. You may obtain a copy of
  * the License at
  *
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  * License for the specific language governing permissions and limitations under
  * the License.
  */

 package com.google.gwt.dev.codeserver;

 import com.google.gwt.core.ext.TreeLogger;
 import com.google.gwt.core.ext.UnableToCompleteException;
 import com.google.gwt.dev.json.JsonArray;
 import com.google.gwt.dev.json.JsonObject;
 import com.google.gwt.thirdparty.org.eclipse.jetty.http.MimeTypes;
 import com.google.gwt.thirdparty.org.eclipse.jetty.io.Buffer;
 import com.google.gwt.thirdparty.org.eclipse.jetty.server.AbstractHttpConnection;
 import com.google.gwt.thirdparty.org.eclipse.jetty.server.Request;
 import com.google.gwt.thirdparty.org.eclipse.jetty.server.Server;
 import com.google.gwt.thirdparty.org.eclipse.jetty.server.nio.SelectChannelConnector;
 import com.google.gwt.thirdparty.org.eclipse.jetty.servlet.FilterHolder;
 import com.google.gwt.thirdparty.org.eclipse.jetty.servlet.ServletContextHandler;
 import com.google.gwt.thirdparty.org.eclipse.jetty.servlet.ServletHolder;
 import com.google.gwt.thirdparty.org.eclipse.jetty.servlets.GzipFilter;

 import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileReader;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.PrintWriter;
 import java.util.EnumSet;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;

 import javax.servlet.ServletException;
 import javax.servlet.DispatcherType;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;

 /**
  * The web server for Super Dev Mode, also known as the code server. The URLs handled include:
  * <ul>
  *   <li>HTML pages for the front page and module pages</li>
  *   <li>JavaScript that implementing the bookmarklets</li>
  *   <li>The web API for recompiling a GWT app</li>
  *   <li>The output files and log files from the GWT compiler</li>
  *   <li>Java source code (for source-level debugging)</li>
  * </ul>
  *
  * <p>EXPERIMENTAL. There is no authentication, encryption, or XSS protection, so this server is
  * only safe to run on localhost.</p>
  */
 public class WebServer {

   private static final Pattern SAFE_DIRECTORY =
       Pattern.compile("([a-zA-Z0-9_-]+\\.)*[a-zA-Z0-9_-]+"); // no extension needed

   private static final Pattern SAFE_FILENAME =
       Pattern.compile("([a-zA-Z0-9_-]+\\.)+[a-zA-Z0-9_-]+"); // an extension is required

   private static final Pattern SAFE_MODULE_PATH =
       Pattern.compile("/(" + SAFE_DIRECTORY + ")/$");

   static final Pattern SAFE_DIRECTORY_PATH =
       Pattern.compile("/(" + SAFE_DIRECTORY + "/)+$");

   /* visible for testing */
   static final Pattern SAFE_FILE_PATH =
       Pattern.compile("/(" + SAFE_DIRECTORY + "/)+" + SAFE_FILENAME + "$");

   private static final Pattern SAFE_CALLBACK =
       Pattern.compile("([a-zA-Z_][a-zA-Z0-9_]*\\.)*[a-zA-Z_][a-zA-Z0-9_]*");

   private static final MimeTypes MIME_TYPES = new MimeTypes();

   private final SourceHandler handler;

   private final Modules modules;

   private final String bindAddress;
   private final int port;
   private final TreeLogger logger;
   private Server server;

   WebServer(SourceHandler handler, Modules modules, String bindAddress, int port,
       TreeLogger logger) {
     this.handler = handler;
     this.modules = modules;
     this.bindAddress = bindAddress;
     this.port = port;
     this.logger = logger;
   }

   public void start() throws UnableToCompleteException {

     SelectChannelConnector connector = new SelectChannelConnector();
     connector.setHost(bindAddress);
     connector.setPort(port);
     connector.setReuseAddress(false);
     connector.setSoLingerTime(0);

     Server server = new Server();
     server.addConnector(connector);

     ServletContextHandler handler = new ServletContextHandler(ServletContextHandler.SESSIONS);
     handler.setContextPath("/");
     handler.addServlet(new ServletHolder(new HttpServlet() {
       @Override
       protected void doGet(HttpServletRequest request, HttpServletResponse response)
           throws ServletException, IOException {
         handleRequest(request.getPathInfo(), request, response);
       }
     }), "/*");
     handler.addFilter(GzipFilter.class, "/*", EnumSet.allOf(DispatcherType.class));
     server.setHandler(handler);
     try {
       server.start();
     } catch (Exception e) {
       logger.log(TreeLogger.ERROR, "cannot start web server", e);
       throw new UnableToCompleteException();
     }
     this.server = server;
   }

   public int getPort() {
     return port;
   }

   public void stop() throws Exception {
     server.stop();
     server = null;
   }

   /**
    * Returns the location of the compiler output. (Changes after every recompile.)
    */
   public File getCurrentWarDir(String moduleName) {
     return modules.get(moduleName).getWarDir();
   }

   private void handleRequest(String target, HttpServletRequest request,
       HttpServletResponse response)
       throws IOException {

     if (request.getMethod().equalsIgnoreCase("get")) {
       doGet(target, request, response);
     }
   }

   private void doGet(String target, HttpServletRequest request, HttpServletResponse response)
       throws IOException {

     if (!target.endsWith(".cache.js")) {
       // Make sure IE9 doesn't cache any pages.
       // (Nearly all pages may change on server restart.)
       PageUtil.setNoCacheHeaders(response);
     }

     if (target.equals("/")) {
       setHandled(request);
       JsonObject config = makeConfig();
       PageUtil.sendJsonAndHtml("config", config, "frontpage.html", response, logger);
       return;
     }

     if (target.equals("/dev_mode_on.js")) {
       setHandled(request);
       JsonObject config = makeConfig();
       PageUtil
           .sendJsonAndJavaScript("__gwt_codeserver_config", config, "dev_mode_on.js", response,
               logger);
       return;
     }

     // Recompile on request from the bookmarklet.
     // This is a GET because a bookmarklet can call it from a different origin (JSONP).
     if (target.startsWith("/recompile/")) {
       setHandled(request);
       String moduleName = target.substring("/recompile/".length());
       ModuleState moduleState = modules.get(moduleName);
       if (moduleState == null) {
         response.sendError(HttpServletResponse.SC_NOT_FOUND);
         logger.log(TreeLogger.WARN, "not found: " + target);
         return;
       }

       // We are passing properties from an unauthenticated GET request directly to the compiler.
       // This should be safe, but only because these are binding properties. For each binding
       // property, you can only choose from a set of predefined values. So all an attacker can do is
       // cause a spurious recompile, resulting in an unexpected permutation being loaded later.
       //
       // It would be unsafe to allow a configuration property to be changed.
       boolean ok = moduleState.recompile(getBindingProperties(request));

       JsonObject config = makeConfig();
       config.put("status", ok ? "ok" : "failed");
       sendJsonpPage(config, request, response);
       return;
     }

     if (target.startsWith("/log/")) {
       setHandled(request);
       String moduleName = target.substring("/log/".length());
       File file = modules.get(moduleName).getCompileLog();
       sendLogPage(moduleName, file, response);
       return;
     }

     if (target.equals("/favicon.ico")) {
       InputStream faviconStream = getClass().getResourceAsStream("favicon.ico");
       if (faviconStream != null) {
         setHandled(request);
         // IE8 will not load the favicon in an img tag with the default MIME type,
         // so use "image/x-icon" instead.
         PageUtil.sendStream("image/x-icon", faviconStream, response);
       }
       return;
     }

     if (target.equals("/policies/")) {
       setHandled(request);
       sendPolicyIndex(response);
       return;
     }

     Matcher matcher = SAFE_MODULE_PATH.matcher(target);
     if (matcher.matches()) {
       setHandled(request);
       sendModulePage(matcher.group(1), response);
       return;
     }

     matcher = SAFE_DIRECTORY_PATH.matcher(target);
     if (matcher.matches() && handler.isSourceMapRequest(target)) {
       setHandled(request);
       handler.handle(target, request, response);
       return;
     }

     matcher = SAFE_FILE_PATH.matcher(target);
     if (matcher.matches()) {
       setHandled(request);
       if (handler.isSourceMapRequest(target)) {
         handler.handle(target, request, response);
         return;
       }
       if (target.startsWith("/policies/")) {
         sendPolicyFile(target, response);
         return;
       }
       sendOutputFile(target, request, response);
       return;
     }

     logger.log(TreeLogger.WARN, "ignored get request: " + target);
   }

   private void sendOutputFile(String target, HttpServletRequest request,
       HttpServletResponse response) throws IOException {

     int secondSlash = target.indexOf('/', 1);
     String moduleName = target.substring(1, secondSlash);
     ModuleState moduleState = modules.get(moduleName);

     File file = moduleState.getOutputFile(target);
     if (!file.isFile()) {
       // perhaps it's compressed
       file = moduleState.getOutputFile(target + ".gz");
       if (!file.isFile()) {
         response.sendError(HttpServletResponse.SC_NOT_FOUND);
         logger.log(TreeLogger.WARN, "not found: " + file.toString());
         return;
       }
       if (!request.getHeader("Accept-Encoding").contains("gzip")) {
         response.sendError(HttpServletResponse.SC_NOT_IMPLEMENTED);
         logger.log(TreeLogger.WARN, "client doesn't accept gzip; bailing");
         return;
       }
       response.setHeader("Content-Encoding", "gzip");
     }

     if (target.endsWith(".cache.js")) {
       response.setHeader("X-SourceMap", sourceMapLocationForModule(moduleName));
     }
     response.setHeader("Access-Control-Allow-Origin", "*");
     String mimeType = guessMimeType(target);
     PageUtil.sendFile(mimeType, file, response);
   }

   private void sendModulePage(String moduleName, HttpServletResponse response) throws IOException {
     ModuleState module = modules.get(moduleName);
     if (module == null) {
       response.sendError(HttpServletResponse.SC_NOT_FOUND);
       logger.log(TreeLogger.WARN, "module not found: " + moduleName);
       return;
     }
     PageUtil
         .sendJsonAndHtml("config", module.getTemplateVariables(), "modulepage.html", response,
             logger);
   }

   private void sendPolicyIndex(HttpServletResponse response) throws IOException {

     response.setContentType("text/html");

     HtmlWriter out = new HtmlWriter(response.getWriter());

     out.startTag("html").nl();
     out.startTag("head").nl();
     out.startTag("title").text("Policy Files").endTag("title").nl();
     out.endTag("head");
     out.startTag("body");

     out.startTag("h1").text("Policy Files").endTag("h1").nl();

     for (String moduleName : modules) {
       ModuleState module = modules.get(moduleName);
       File manifest = module.getExtraFile("rpcPolicyManifest/manifest.txt");
       if (manifest.isFile()) {
         out.startTag("h2").text(moduleName).endTag("h2").nl();

         out.startTag("table").nl();
         String text = PageUtil.loadFile(manifest);
         for (String line : text.split("\n")) {
           line = line.trim();
           if (line.isEmpty() || line.startsWith("#")) {
             continue;
           }
           String[] fields = line.split(", ");
           if (fields.length < 2) {
             continue;
           }

           String serviceName = fields[0];
           String policyFileName = fields[1];

           String serviceUrl = SourceHandler.SOURCEMAP_PATH + moduleName + "/" +
               serviceName.replace('.', '/') + ".java";
           String policyUrl = "/policies/" + policyFileName;

           out.startTag("tr");

           out.startTag("td");
           out.startTag("a", "href=", serviceUrl).text(serviceName).endTag("a");
           out.endTag("td");

           out.startTag("td");
           out.startTag("a", "href=", policyUrl).text(policyFileName).endTag("a");
           out.endTag("td");

           out.endTag("tr").nl();
         }
         out.endTag("table").nl();
       }
     }

     out.endTag("body").nl();
     out.endTag("html").nl();
   }

   private void sendPolicyFile(String target, HttpServletResponse response) throws IOException {
     int secondSlash = target.indexOf('/', 1);
     if (secondSlash < 1) {
       response.sendError(HttpServletResponse.SC_NOT_FOUND);
       return;
     }
     String rest = target.substring(secondSlash + 1);
     if (rest.contains("/") || !rest.endsWith(".gwt.rpc")) {
       response.sendError(HttpServletResponse.SC_NOT_FOUND);
       return;
     }

     for (String moduleName : modules) {
       ModuleState module = modules.get(moduleName);
       File policy = module.getOutputFile(moduleName + "/" + rest);
       if (policy.isFile()) {
         PageUtil.sendFile("text/plain", policy, response);
         return;
       }
     }

     logger.log(TreeLogger.Type.WARN, "policy file not found: " + rest);
     response.sendError(HttpServletResponse.SC_NOT_FOUND);
   }

   private JsonObject makeConfig() {
     JsonArray moduleNames = new JsonArray();
     for (String module : modules) {
       moduleNames.add(module);
     }
     JsonObject config = JsonObject.create();
     config.put("moduleNames", moduleNames);
     return config;
   }

   private void sendJsonpPage(JsonObject json, HttpServletRequest request,
       HttpServletResponse response) throws IOException {

     response.setStatus(HttpServletResponse.SC_OK);
     response.setContentType("application/javascript");
     PrintWriter out = response.getWriter();

     String callbackExpression = request.getParameter("_callback");
     if (callbackExpression == null || !SAFE_CALLBACK.matcher(callbackExpression).matches()) {
       logger.log(TreeLogger.ERROR, "invalid callback: " + callbackExpression);
       out.print("/* invalid callback parameter */");
       return;
     }

     out.print(callbackExpression + "(");
     json.write(out);
     out.println(");");
   }

   /**
    * Sends the log file as html with errors highlighted in red.
    */
   private void sendLogPage(String moduleName, File file, HttpServletResponse response)
        throws IOException {
     BufferedReader reader = new BufferedReader(new FileReader(file));

     response.setStatus(HttpServletResponse.SC_OK);
     response.setContentType("text/html");
     response.setHeader("Content-Style-Type", "text/css");

     HtmlWriter out = new HtmlWriter(response.getWriter());
     out.startTag("html").nl();
     out.startTag("head").nl();
     out.startTag("title").text(moduleName + " compile log").endTag("title").nl();
     out.startTag("style").nl();
     out.text(".error { color: red; font-weight: bold; }").nl();
     out.endTag("style").nl();
     out.endTag("head").nl();
     out.startTag("body").nl();
     sendLogAsHtml(reader, out);
     out.endTag("body").nl();
     out.endTag("html").nl();
   }

   private static final Pattern ERROR_PATTERN = Pattern.compile("\\[ERROR\\]");

   /**
    * Copies in to out line by line, escaping each line for html characters and highlighting
    * error lines. Closes <code>in</code> when done.
    */
   private static void sendLogAsHtml(BufferedReader in, HtmlWriter out) throws IOException {
     try {
       out.startTag("pre").nl();
       String line = in.readLine();
       while (line != null) {
         Matcher m = ERROR_PATTERN.matcher(line);
         boolean error = m.find();
         if (error) {
           out.startTag("span", "class=", "error");
         }
         out.text(line);
         if (error) {
           out.endTag("span");
         }
         out.nl(); // the readLine doesn't include the newline.
         line = in.readLine();
       }
       out.endTag("pre").nl();
     } finally {
       in.close();
     }
   }

   /* visible for testing */
   static String guessMimeType(String filename) {
     Buffer mimeType = MIME_TYPES.getMimeByExtension(filename);
     return mimeType != null ? mimeType.toString() : "";
   }

   /**
    * Returns the binding properties from the web page where dev mode is being used. (As passed in
    * by dev_mode_on.js in a JSONP request to "/recompile".)
    */
   private Map<String, String> getBindingProperties(HttpServletRequest request) {
     Map<String, String> result = new HashMap<String, String>();
     for (Object key : request.getParameterMap().keySet()) {
       String propName = (String) key;
       if (!propName.equals("_callback")) {
         result.put(propName, request.getParameter(propName));
       }
     }
     return result;
   }

   public static String sourceMapLocationForModule(String moduleName) {
      return SourceHandler.SOURCEMAP_PATH + moduleName +
          "/gwtSourceMap.json";
   }

   private static void setHandled(HttpServletRequest request) {
     Request baseRequest = (request instanceof Request) ? (Request) request :
         AbstractHttpConnection.getCurrentConnection().getRequest();
     baseRequest.setHandled(true);
   }
 }
	/*
	* Copyright 2011 Google Inc.
	*
	* Licensed under the Apache License, Version 2.0 (the "License"); you may not
	* use this file except in compliance with the License. You may obtain a copy of
	* the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
	* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
	* License for the specific language governing permissions and limitations under
	* the License.
	*/

	package com.google.gwt.dev.codeserver;

	import com.google.gwt.core.ext.TreeLogger;
	import com.google.gwt.core.ext.UnableToCompleteException;
	import com.google.gwt.dev.json.JsonArray;
	import com.google.gwt.dev.json.JsonObject;
	import com.google.gwt.thirdparty.org.eclipse.jetty.http.MimeTypes;
	import com.google.gwt.thirdparty.org.eclipse.jetty.io.Buffer;
	import com.google.gwt.thirdparty.org.eclipse.jetty.server.AbstractHttpConnection;
	import com.google.gwt.thirdparty.org.eclipse.jetty.server.Request;
	import com.google.gwt.thirdparty.org.eclipse.jetty.server.Server;
	import com.google.gwt.thirdparty.org.eclipse.jetty.server.nio.SelectChannelConnector;
	import com.google.gwt.thirdparty.org.eclipse.jetty.servlet.FilterHolder;
	import com.google.gwt.thirdparty.org.eclipse.jetty.servlet.ServletContextHandler;
	import com.google.gwt.thirdparty.org.eclipse.jetty.servlet.ServletHolder;
	import com.google.gwt.thirdparty.org.eclipse.jetty.servlets.GzipFilter;

	import java.io.BufferedReader;
	import java.io.File;
	import java.io.FileReader;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.PrintWriter;
	import java.util.EnumSet;
	import java.util.HashMap;
	import java.util.Map;
	import java.util.regex.Matcher;
	import java.util.regex.Pattern;

	import javax.servlet.ServletException;
	import javax.servlet.DispatcherType;
	import javax.servlet.http.HttpServlet;
	import javax.servlet.http.HttpServletRequest;
	import javax.servlet.http.HttpServletResponse;

	/**
	* The web server for Super Dev Mode, also known as the code server. The URLs handled include:
	* <ul>
	* <li>HTML pages for the front page and module pages</li>
	* <li>JavaScript that implementing the bookmarklets</li>
	* <li>The web API for recompiling a GWT app</li>
	* <li>The output files and log files from the GWT compiler</li>
	* <li>Java source code (for source-level debugging)</li>
	* </ul>
	*
	* <p>EXPERIMENTAL. There is no authentication, encryption, or XSS protection, so this server is
	* only safe to run on localhost.</p>
	*/
	public class WebServer {

	private static final Pattern SAFE_DIRECTORY =
	Pattern.compile("([a-zA-Z0-9_-]+\\.)*[a-zA-Z0-9_-]+"); // no extension needed

	private static final Pattern SAFE_FILENAME =
	Pattern.compile("([a-zA-Z0-9_-]+\\.)+[a-zA-Z0-9_-]+"); // an extension is required

	private static final Pattern SAFE_MODULE_PATH =
	Pattern.compile("/(" + SAFE_DIRECTORY + ")/$");

	static final Pattern SAFE_DIRECTORY_PATH =
	Pattern.compile("/(" + SAFE_DIRECTORY + "/)+$");

	/* visible for testing */
	static final Pattern SAFE_FILE_PATH =
	Pattern.compile("/(" + SAFE_DIRECTORY + "/)+" + SAFE_FILENAME + "$");

	private static final Pattern SAFE_CALLBACK =
	Pattern.compile("([a-zA-Z_][a-zA-Z0-9_]\\.)[a-zA-Z_][a-zA-Z0-9_]*");

	private static final MimeTypes MIME_TYPES = new MimeTypes();

	private final SourceHandler handler;

	private final Modules modules;

	private final String bindAddress;
	private final int port;
	private final TreeLogger logger;
	private Server server;

	WebServer(SourceHandler handler, Modules modules, String bindAddress, int port,
	TreeLogger logger) {
	this.handler = handler;
	this.modules = modules;
	this.bindAddress = bindAddress;
	this.port = port;
	this.logger = logger;
	}

	public void start() throws UnableToCompleteException {

	SelectChannelConnector connector = new SelectChannelConnector();
	connector.setHost(bindAddress);
	connector.setPort(port);
	connector.setReuseAddress(false);
	connector.setSoLingerTime(0);

	Server server = new Server();
	server.addConnector(connector);

	ServletContextHandler handler = new ServletContextHandler(ServletContextHandler.SESSIONS);
	handler.setContextPath("/");
	handler.addServlet(new ServletHolder(new HttpServlet() {
	@Override
	protected void doGet(HttpServletRequest request, HttpServletResponse response)
	throws ServletException, IOException {
	handleRequest(request.getPathInfo(), request, response);
	}
	}), "/*");
	handler.addFilter(GzipFilter.class, "/*", EnumSet.allOf(DispatcherType.class));
	server.setHandler(handler);
	try {
	server.start();
	} catch (Exception e) {
	logger.log(TreeLogger.ERROR, "cannot start web server", e);
	throw new UnableToCompleteException();
	}
	this.server = server;
	}

	public int getPort() {
	return port;
	}

	public void stop() throws Exception {
	server.stop();
	server = null;
	}

	/**
	* Returns the location of the compiler output. (Changes after every recompile.)
	*/
	public File getCurrentWarDir(String moduleName) {
	return modules.get(moduleName).getWarDir();
	}

	private void handleRequest(String target, HttpServletRequest request,
	HttpServletResponse response)
	throws IOException {

	if (request.getMethod().equalsIgnoreCase("get")) {
	doGet(target, request, response);
	}
	}

	private void doGet(String target, HttpServletRequest request, HttpServletResponse response)
	throws IOException {

	if (!target.endsWith(".cache.js")) {
	// Make sure IE9 doesn't cache any pages.
	// (Nearly all pages may change on server restart.)
	PageUtil.setNoCacheHeaders(response);
	}

	if (target.equals("/")) {
	setHandled(request);
	JsonObject config = makeConfig();
	PageUtil.sendJsonAndHtml("config", config, "frontpage.html", response, logger);
	return;
	}

	if (target.equals("/dev_mode_on.js")) {
	setHandled(request);
	JsonObject config = makeConfig();
	PageUtil
	.sendJsonAndJavaScript("__gwt_codeserver_config", config, "dev_mode_on.js", response,
	logger);
	return;
	}

	// Recompile on request from the bookmarklet.
	// This is a GET because a bookmarklet can call it from a different origin (JSONP).
	if (target.startsWith("/recompile/")) {
	setHandled(request);
	String moduleName = target.substring("/recompile/".length());
	ModuleState moduleState = modules.get(moduleName);
	if (moduleState == null) {
	response.sendError(HttpServletResponse.SC_NOT_FOUND);
	logger.log(TreeLogger.WARN, "not found: " + target);
	return;
	}

	// We are passing properties from an unauthenticated GET request directly to the compiler.
	// This should be safe, but only because these are binding properties. For each binding
	// property, you can only choose from a set of predefined values. So all an attacker can do is
	// cause a spurious recompile, resulting in an unexpected permutation being loaded later.
	//
	// It would be unsafe to allow a configuration property to be changed.
	boolean ok = moduleState.recompile(getBindingProperties(request));

	JsonObject config = makeConfig();
	config.put("status", ok ? "ok" : "failed");
	sendJsonpPage(config, request, response);
	return;
	}

	if (target.startsWith("/log/")) {
	setHandled(request);
	String moduleName = target.substring("/log/".length());
	File file = modules.get(moduleName).getCompileLog();
	sendLogPage(moduleName, file, response);
	return;
	}

	if (target.equals("/favicon.ico")) {
	InputStream faviconStream = getClass().getResourceAsStream("favicon.ico");
	if (faviconStream != null) {
	setHandled(request);
	// IE8 will not load the favicon in an img tag with the default MIME type,
	// so use "image/x-icon" instead.
	PageUtil.sendStream("image/x-icon", faviconStream, response);
	}
	return;
	}

	if (target.equals("/policies/")) {
	setHandled(request);
	sendPolicyIndex(response);
	return;
	}

	Matcher matcher = SAFE_MODULE_PATH.matcher(target);
	if (matcher.matches()) {
	setHandled(request);
	sendModulePage(matcher.group(1), response);
	return;
	}

	matcher = SAFE_DIRECTORY_PATH.matcher(target);
	if (matcher.matches() && handler.isSourceMapRequest(target)) {
	setHandled(request);
	handler.handle(target, request, response);
	return;
	}

	matcher = SAFE_FILE_PATH.matcher(target);
	if (matcher.matches()) {
	setHandled(request);
	if (handler.isSourceMapRequest(target)) {
	handler.handle(target, request, response);
	return;
	}
	if (target.startsWith("/policies/")) {
	sendPolicyFile(target, response);
	return;
	}
	sendOutputFile(target, request, response);
	return;
	}

	logger.log(TreeLogger.WARN, "ignored get request: " + target);
	}

	private void sendOutputFile(String target, HttpServletRequest request,
	HttpServletResponse response) throws IOException {

	int secondSlash = target.indexOf('/', 1);
	String moduleName = target.substring(1, secondSlash);
	ModuleState moduleState = modules.get(moduleName);

	File file = moduleState.getOutputFile(target);
	if (!file.isFile()) {
	// perhaps it's compressed
	file = moduleState.getOutputFile(target + ".gz");
	if (!file.isFile()) {
	response.sendError(HttpServletResponse.SC_NOT_FOUND);
	logger.log(TreeLogger.WARN, "not found: " + file.toString());
	return;
	}
	if (!request.getHeader("Accept-Encoding").contains("gzip")) {
	response.sendError(HttpServletResponse.SC_NOT_IMPLEMENTED);
	logger.log(TreeLogger.WARN, "client doesn't accept gzip; bailing");
	return;
	}
	response.setHeader("Content-Encoding", "gzip");
	}

	if (target.endsWith(".cache.js")) {
	response.setHeader("X-SourceMap", sourceMapLocationForModule(moduleName));
	}
	response.setHeader("Access-Control-Allow-Origin", "*");
	String mimeType = guessMimeType(target);
	PageUtil.sendFile(mimeType, file, response);
	}

	private void sendModulePage(String moduleName, HttpServletResponse response) throws IOException {
	ModuleState module = modules.get(moduleName);
	if (module == null) {
	response.sendError(HttpServletResponse.SC_NOT_FOUND);
	logger.log(TreeLogger.WARN, "module not found: " + moduleName);
	return;
	}
	PageUtil
	.sendJsonAndHtml("config", module.getTemplateVariables(), "modulepage.html", response,
	logger);
	}

	private void sendPolicyIndex(HttpServletResponse response) throws IOException {

	response.setContentType("text/html");

	HtmlWriter out = new HtmlWriter(response.getWriter());

	out.startTag("html").nl();
	out.startTag("head").nl();
	out.startTag("title").text("Policy Files").endTag("title").nl();
	out.endTag("head");
	out.startTag("body");

	out.startTag("h1").text("Policy Files").endTag("h1").nl();

	for (String moduleName : modules) {
	ModuleState module = modules.get(moduleName);
	File manifest = module.getExtraFile("rpcPolicyManifest/manifest.txt");
	if (manifest.isFile()) {
	out.startTag("h2").text(moduleName).endTag("h2").nl();

	out.startTag("table").nl();
	String text = PageUtil.loadFile(manifest);
	for (String line : text.split("\n")) {
	line = line.trim();
	if (line.isEmpty() \|\| line.startsWith("#")) {
	continue;
	}
	String[] fields = line.split(", ");
	if (fields.length < 2) {
	continue;
	}

	String serviceName = fields[0];
	String policyFileName = fields[1];

	String serviceUrl = SourceHandler.SOURCEMAP_PATH + moduleName + "/" +
	serviceName.replace('.', '/') + ".java";
	String policyUrl = "/policies/" + policyFileName;

	out.startTag("tr");

	out.startTag("td");
	out.startTag("a", "href=", serviceUrl).text(serviceName).endTag("a");
	out.endTag("td");

	out.startTag("td");
	out.startTag("a", "href=", policyUrl).text(policyFileName).endTag("a");
	out.endTag("td");

	out.endTag("tr").nl();
	}
	out.endTag("table").nl();
	}
	}

	out.endTag("body").nl();
	out.endTag("html").nl();
	}

	private void sendPolicyFile(String target, HttpServletResponse response) throws IOException {
	int secondSlash = target.indexOf('/', 1);
	if (secondSlash < 1) {
	response.sendError(HttpServletResponse.SC_NOT_FOUND);
	return;
	}
	String rest = target.substring(secondSlash + 1);
	if (rest.contains("/") \|\| !rest.endsWith(".gwt.rpc")) {
	response.sendError(HttpServletResponse.SC_NOT_FOUND);
	return;
	}

	for (String moduleName : modules) {
	ModuleState module = modules.get(moduleName);
	File policy = module.getOutputFile(moduleName + "/" + rest);
	if (policy.isFile()) {
	PageUtil.sendFile("text/plain", policy, response);
	return;
	}
	}

	logger.log(TreeLogger.Type.WARN, "policy file not found: " + rest);
	response.sendError(HttpServletResponse.SC_NOT_FOUND);
	}

	private JsonObject makeConfig() {
	JsonArray moduleNames = new JsonArray();
	for (String module : modules) {
	moduleNames.add(module);
	}
	JsonObject config = JsonObject.create();
	config.put("moduleNames", moduleNames);
	return config;
	}

	private void sendJsonpPage(JsonObject json, HttpServletRequest request,
	HttpServletResponse response) throws IOException {

	response.setStatus(HttpServletResponse.SC_OK);
	response.setContentType("application/javascript");
	PrintWriter out = response.getWriter();

	String callbackExpression = request.getParameter("_callback");
	if (callbackExpression == null \|\| !SAFE_CALLBACK.matcher(callbackExpression).matches()) {
	logger.log(TreeLogger.ERROR, "invalid callback: " + callbackExpression);
	out.print("/* invalid callback parameter */");
	return;
	}

	out.print(callbackExpression + "(");
	json.write(out);
	out.println(");");
	}

	/**
	* Sends the log file as html with errors highlighted in red.
	*/
	private void sendLogPage(String moduleName, File file, HttpServletResponse response)
	throws IOException {
	BufferedReader reader = new BufferedReader(new FileReader(file));

	response.setStatus(HttpServletResponse.SC_OK);
	response.setContentType("text/html");
	response.setHeader("Content-Style-Type", "text/css");

	HtmlWriter out = new HtmlWriter(response.getWriter());
	out.startTag("html").nl();
	out.startTag("head").nl();
	out.startTag("title").text(moduleName + " compile log").endTag("title").nl();
	out.startTag("style").nl();
	out.text(".error { color: red; font-weight: bold; }").nl();
	out.endTag("style").nl();
	out.endTag("head").nl();
	out.startTag("body").nl();
	sendLogAsHtml(reader, out);
	out.endTag("body").nl();
	out.endTag("html").nl();
	}

	private static final Pattern ERROR_PATTERN = Pattern.compile("\\[ERROR\\]");

	/**
	* Copies in to out line by line, escaping each line for html characters and highlighting
	* error lines. Closes <code>in</code> when done.
	*/
	private static void sendLogAsHtml(BufferedReader in, HtmlWriter out) throws IOException {
	try {
	out.startTag("pre").nl();
	String line = in.readLine();
	while (line != null) {
	Matcher m = ERROR_PATTERN.matcher(line);
	boolean error = m.find();
	if (error) {
	out.startTag("span", "class=", "error");
	}
	out.text(line);
	if (error) {
	out.endTag("span");
	}
	out.nl(); // the readLine doesn't include the newline.
	line = in.readLine();
	}
	out.endTag("pre").nl();
	} finally {
	in.close();
	}
	}

	/* visible for testing */
	static String guessMimeType(String filename) {
	Buffer mimeType = MIME_TYPES.getMimeByExtension(filename);
	return mimeType != null ? mimeType.toString() : "";
	}

	/**
	* Returns the binding properties from the web page where dev mode is being used. (As passed in
	* by dev_mode_on.js in a JSONP request to "/recompile".)
	*/
	private Map<String, String> getBindingProperties(HttpServletRequest request) {
	Map<String, String> result = new HashMap<String, String>();
	for (Object key : request.getParameterMap().keySet()) {
	String propName = (String) key;
	if (!propName.equals("_callback")) {
	result.put(propName, request.getParameter(propName));
	}
	}
	return result;
	}

	public static String sourceMapLocationForModule(String moduleName) {
	return SourceHandler.SOURCEMAP_PATH + moduleName +
	"/gwtSourceMap.json";
	}

	private static void setHandled(HttpServletRequest request) {
	Request baseRequest = (request instanceof Request) ? (Request) request :
	AbstractHttpConnection.getCurrentConnection().getRequest();
	baseRequest.setHandled(true);
	}
	}